//抽象类
public abstract class  A {

    private String name;
    public int age;

    public A() {
    }

    public A(String name, int age) {
        this.name = name;
        this.age = age;
    }

    public int getAge() {
        return age;
    }

    public void setAge(int age) {
        this.age = age;
    }

    public String getName() {
        return name;
    }

    public void setName(String name) {
        this.name = name;
    }

    //抽象方法：必须用abstract修饰,只有方法签名,一定不能有方法体
    public abstract void run();
}
